Pituitary I

Question 1

What size are microadenomas and macroadenomas?

Answer 1

Microadenoma <= 1cm

Macroadenoma >1cm

Question 2

What can a non-functioning pituitary adenoma cause?

Answer 2

Compression of optic chiasm and other structures, hypoadrenalism, hypothyroidism, hypogonadism, diabetes insipidus, GH deficiency

Question 3

How are non-functioning pituitary adenomas managed?

Answer 3

Transsphenoidal surgery, replace hormones

Question 4

What are physiological causes of raised prolactin?

Answer 4

Breast feeding, pregnancy, sleep, stress

Question 5

What drugs can cause raised prolactin?

Answer 5

Dopamine antagonists, antipsychotics, antidepressants, oestrogen, cocaine

Question 6

What are some pathologies that cause raised prolactin?

Answer 6

Hypothyroidism, stalk lesions, prolactinoma

Question 7

What are the symptoms of a prolactinoma in a female?

Answer 7

Early presentation, galactorrhoea, menstrual irregularity, amenorrhoea, infertility

Question 8

What are the symptoms of a prolactinoma in a male?

Answer 8

Late presentation, impotence, visual field abnormalities, headache, anterior pituitary malfunction

Question 9

What investigations can be done for prolactinomas?

Answer 9

Serum prolactin concentration (raised)
MRI = micro/macroprolactinoma, pituitary stalk, optic chiasm
Visual fields = bilateral hemianopia
Pituitary function tests

Question 10

What drug can be used to treat prolactinomas?

Answer 10

Dopamine antagonists = bromocriptine (3x daily orally), quinagolide (once daily orally), cabergoline (usually used, least side effects, once/twice week orally)

Question 11

How successful are dopamine agonists in treating prolactinomas?

Answer 11

Very = prolactin normalised in 96%, menstruation regained in 94%, pregnancy rate 91%, tumour shrinkage

Question 12

What are the side effects of prolactinomas?

Answer 12

Nausea/vomiting, low mood, fibrosis (heart valves/retroperitoneal)

Question 13

What causes acromegaly?

Answer 13

Excess GH

Question 14

What are the features of acromegaly?

Answer 14

Giant, thickened soft tissue (large jaw and hands), sweaty, snoring/sleep apnoea, hypertension, cardiac failure, headaches, diabetes, visual field abnormalities, hypopituitarism, early CV death, colonic polyps/cancer

Question 15

How is acromegaly diagnosed?

Answer 15

IGF-1 = age and sex matched
GTT = suppression test, 75g oral then check GH at 0/30/60/90/120mins (GH unchanged, paradoxical rise)
Visual field and pituitary function tests
CT or MRI pituitary scan

Question 16

How successful is surgery in treating acromegaly?

Answer 16

90% cure if microadenoma, 50% cure if macroadenoma

Question 17

How successful is radiotherapy alone in treating acromegaly?

Answer 17

25% success at three years

Question 18

What drugs can be used to treat acromegaly?

Answer 18

Somatostatin analogues = sandostatin LAR, lanreotide
Dopamine agonists = cabergoline
Pegvisomat = GH antagonist

Question 19

What are some features of somatostatin analogues used to treat acromegaly?

Answer 19

Reduces GH in most patients

Tumour shrinkage = 30-50% decrease in size, takes 6-12 months, re-expansion 6 weeks after stopping

Question 20

How are somatostatin analogues used to treat acromegaly pre-operatively?

Answer 20

Relieves headaches within 1hr, improves outcomes

Question 21

What are some side effects of somatostatin analogues?

Answer 21

Local stinging, flatulence, diarrhoea, abdominal pains, gallstones (60%, occur by 6 months, risk of biliary colic)

Question 22

What is the dosage of somatostatin analogues when treating acromegaly?

Answer 22

Sandostatin LAR = 10-30mg/28 days IM
Lanreotide autogel = 60-12-mg/28days SC
Pasireotide LAR = 40-60mg/28days IM

Question 23

What are some features of dopamine agonists used to treat acromegaly?

Answer 23

Cabergoline up to 3g weekly, work in around 10-15%, better if co-secreting prolactin

Question 24

What are some features of pegvisomat used to treat acromegaly?

Answer 24

SC injection 10-30mg daily, 85% response rate, tumour size doesn’t decrease, IGF-1 decreases but serum GH increases, last line treatment

Question 25

What must be managed in patients with acromegaly?

Answer 25

Cancer surveillance = colon and tubo-villous adenoma

CV risk factor management